Wave-fields separation for seismic recorders distributed at non-flat recording surfaces

Abstract

Apparatus, computer instructions and method for separating up-going and down-going wave fields (U, D) from seismic data recorded within or beneath a body of water, or in general below the surface of the earth. The method includes a step of receiving seismic data (Po, Zo) recorded in the time-space domain with seismic recorders distributed on a first datum, wherein the first datum is non-flat; a step of establishing a mathematical relation between transformed seismic data (P, Z) and the up-going and down-going wave fields (U, D) on a second planar datum; and a step of solving with an inversion procedure, run on a processor, the mathematical relation to obtain the up-going and down-going wave fields (U, D) for the second datum. The second datum is different from the first datum.

Description

BACKGROUND[0001]Technical Field[0002]Embodiments of the subject matter disclosed herein generally relate to methods and systems and, more particularly, to mechanisms and techniques for separating up-going and down-going wave fields from seismic data recorded underwater or under the surface of the earth by a seismic receiver.[0003]Discussion of the Background[0004]Offshore and onshore drilling is an expensive process. Thus, those engaged in such a costly undertaking invest substantially in geophysical surveys to more accurately decide where to drill in order to avoid a well with no or non-commercial quantities of hydrocarbons.[0005]Marine and land seismic data acquisition and processing generate an image of the geophysical structure (subsurface). While this image / profile does not provide a precise location for oil and gas reservoirs, it suggests, to those trained in the field, the presence or absence of oil and / or gas reservoirs. Thus, providing a high-resolution image of the subsurf...

AI Technical Summary

Benefits of technology

This approach effectively separates up-going and down-going wave fields, reducing noise and improving the accuracy of seismic imaging by correcting for the non-flat acquisition surface, resulting in a more precise subsurface image.

Problems solved by technology

Offshore and onshore drilling is an expensive process.

In essence, interference between primary and ghost arrivals causes notches or gaps in the frequency content, and these notches cannot be removed without the combined use of advanced acquisition and processing techniques.

However, the ocean bottom is a non-planar acquisition surface.

Thus, for these situations, the planar surface assumption fails, and the collected data may generate spurious effects in the final image unless it is corrected.

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